metadata only access
An improvement has been made to Rouard's method for the analysis of fiber and waveguide gratings. The real reflectivity of each interface is used instead of an approximate value obtained by coupled-mode theory. The improved Rouard's method becomes a complete Rouard's method and an exact method. It is simple and independent on coupled-mode theory for no calculation of coupling coefficient required. Numerical examples of uniform and nonuniform gratings have been given.